In My Opinion (Re-rebuttal)

I write to respond to two critiques of an article I wrote in the last APSF Newsletter, warning practitioners about the patient deaths that have occurred with the Abbott Lifecare 4100 PCA Plus II infusion pump.¹ The APSF deserves to be congratulated for publishing that article despite the fact that Abbott is a Grand Patron of the APSF. This decision sends a strong and important message to the anesthesiology community – patient safety comes first.

In this critique of my article, Dr. Andre mentions that he was asked to make his opinions on the matter of PCA safety “at the request of Abbott Labs”.² However, he does not mention that he previously served as a paid consultant to Abbott Laboratories.³

I agree with Dr. Andre about the value of a systems approach to design. This issue has been consistently recognized in the human factors literature. For example, cognitive work analysis is a systems approach to the design of information support systems to help workers in complex sociotechnical domains, of which medicine is one example.⁴ This approach represents a very broad view, incorporating technical, psychological, social, and organizational dimensions in one integrated and coherent framework.

The majority of Dr. Andre’s three-page long rebuttal is devoted to explaining why the purported fix I proposed is flawed. My article was limited to stating that: a) several patients have died while connected to the Lifecare 4100; b) these deaths were associated with programming errors; and c) reports in the literature have linked these errors to human factors inadequacies in the design of the current PCA interface (i.e., the initial presentation of the minimum medication concentration value in one mode of operation). My intent was to bring this information to the attention of the anesthesiology community so that patient safety could be improved, a goal that we all share. No “quick fix” was proposed. In our published research on the Lifecare 4100, my colleagues and I also did notÑand in fact, could notÑpropose a solution to this specific problem.⁵ First, we did not conduct any clinical trials of an alternative interface, and second, we only learned of the deaths associated with the Lifecare 4100 after our research was published.

I agree with Dr. Andre that any solution that is intended to reduce the number of deaths due to programming errors must be examined very closely and carefully, preferably following a human factors systems design approach. It is for this reason that I did not propose a quick fix in my article. Nevertheless, the fact that there may very well be legitimate debate about the best way to fix the problem does not prevent Dr. Andre or Abbott from taking some kind of action to improve patient safety.

I am pleased to see from Dr. McLeskey’s reply to my article that Abbott is intending to release a next-generation device in 2001.⁶ That device appears to have the potential to eliminate programming errors through bar code technology. However, this is not the first time that Abbott has said that it will change the design of the Lifecare 4100.⁷

In the meantime, the existing version of the Lifecare 4100 is still being used on a daily basis in hospitals around the world, including nearly 4,000 hospitals in the US alone.⁸ Because of my beliefs, I am still concerned that patients continue to remain at risk for accidental drug overdoses and associated morbidity and even mortality while the current-generation device is being used.

Dr. McLeskey is correct in stating that the number of reported deaths associated with programming errors on the Lifecare 4100 is very small compared to the 22 million patients who have not experienced any problems. For example, the ECRI and ISMP investigations I cited in my original article report three, and perhaps four, deaths.^9,10 However, it is well-known that incidents are vastly under-reported in medicine. Studies have shown that only about 5% of the incidents that occur actually get reported.^11,12 “This suggests that using [incident reports] as a primary data source to study drug-related complications will be misleading”.¹¹

Dr.McLeskey is also correct in stating that no technology is risk free. The more important question is whether we have enough information to readily reduce the number of deaths associated with the use of this device. For the reasons outlined in my original article, I believe that it has been possible to introduce a next generation product that “will feature numerous design and safety improvements”.⁶

I am pleased that Abbott is currently intending to take this important step. Abbott started their efforts to redesign the Lifecare 4100 in 1996.⁶ That was the year that ISMP first issued a safety brief on the Lifecare 4100.¹³ Since that time, ISMP has published numerous articles about how inadequate attention to human factors engineering in PCA pump design can threaten patient safety.^7,10,14-18 During this time, more patients are alleged to have died of overdoses while connected to the Lifecare 4100.^10,17,19 Meanwhile, Abbott has yet to issue a product recall.²⁰ Moreover, to my knowledge, Abbott has also not issued a proactive letter to hospitals to warn them of the conditions under which patient deaths appear to continue to occur.²⁰ Abbott did, however, issue a letter to clinicians in 1997 implying that the ECRI report of deaths associated with the Lifecare 4100 was inaccurate.²¹ That letter did not acknowledge that a device redesign could improve patient safety.

Perhaps, in the future, medical device manufacturers or government regulators will take actions so that we can collectively “recognize, anticipate, and defend against new paths to failure that arise as organizations and technology change, before any patient is injured”.²²

Dr. Vicente is Professor and Director, Cognitive Engineering Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Ontario, Canada.

References

1. Vicente, KJ. Human factors researcher alarmed by deaths during PCA. APSF Newsletter 2000; 15(3): 36-37.
2. Andre, AD. Human factors consultant rebuts PCA pump danger charges. APSF Newsletter 2000; 15(3): 37-39.
3. Client list for Interface Analysis Associates (www.interface-analysis.com/portfolio/portfolio.0.html). August 8, 2000. 4. Vicente, KJ. Cognitive work analysis: Toward safe, productive, and healthy computer-based work. Mahwah, NJ: Lawrence Erlbaum & Associates, 1999.
5. Lin L, et al. Applying human factors to the design of medical equipment: Patient-controlled analgesia. Journal of Clinical Monitoring and Computing 1998; 14: 253-263.
6. McLeskey, CH. Abbott addresses medication errors through advanced PCA technology. APSF Newsletter 2000; 15(3): 36-37.
7. Institute for Safe Medication Practices. Safety briefs. ISMP Medication Safety Alert 1996; 1(20).
8. Lifecare PCA Plus II Infuser (www.abbott.com/ pain/pain_management.html). October 24, 2000.
9. ECRI. Abbott PCA Plus II patient-controlled analgesia pumps prone to misprogramming resulting in narcotic overinfusions. Health Devices 1997;26(10):389-391.
10. Institute for Safe Medication Practices. Evidence builds: Lack of focus on human factors allows error-prone devices. ISMP Medication Safety Alert 1999; 4(15).
11. Cullen DJ, et al. The incident reporting system does not detect adverse drug events: A problem for quality improvement. Joint Commission Journal of Quality Improvement 1995; 21(10): 541-552.
12. Gardner S, Flack, M. Designing a medical device surveillance network. FDA report to Congress. 1999.
13. Institute for Safe Medication Practices. Safety briefs. ISMP Medication Safety Alert 1996; 1(9).
14. Institute for Safe Medication Practices. Safety briefs. ISMP Medication Safety Alert 1996; 1(12).
15. Institute for Safe Medication Practices. Safety briefs. ISMP Medication Safety Alert 1996; 1(25).
16. Institute for Safe Medication Practices. Frequently occurring problems noted during ISMP evaluations of hospital medications systems Ð Part 2. ISMP Medication Safety Alert 1998; 3(12).
17. Institute for Safe Medication Practices. Design flaw predisposes Abbott Lifecare PCA Plus II pump to dangerous medication errors. ISMP Medication Safety Alert 2000; 5(11).
18. Institute for Safe Medication Practices. Safety briefs. ISMP Medication Safety Alert 2000; 5(14).
19. St. John P. Drug pump’s deadly trail. Tallahassee Democrat, Sunday, May 28, 2000. (www.tdo.com/local /tmh/0528.loc.pump.htm).
20. Cohen MR. Personal communication, October 25, 2000.
21. Letter dated October 29, 1997 from the Hospital Products Division of Abbott Laboratories.
22. Woods DD. Behind human error: Human factors research to improve patient safety. Oral testimony at National Summit on Medical Errors and Patient Safety Research. Quality Interagency Coordination Task Force (QuIC) and Agency for Healthcare Research and Quality (AHRQ), September 11, 2000. (http://www.quic.gov/summit/wwoods.htm).